CA2156606A1

CA2156606A1 - Lubricant compositions containing complexes of alkoxylated amine, acid, and adenine

Info

Publication number: CA2156606A1
Application number: CA002156606A
Authority: CA
Inventors: Jacob Joseph Habeeb; Morton Beltzer
Original assignee: Individual
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1993-02-22
Filing date: 1994-02-22
Publication date: 1994-09-01
Also published as: DE69404447T2; JPH09502422A; WO1994019437A1; EP0684979A1; DE69404447D1; EP0684979B1

Abstract

A composition of matter useful in lubricating oil for reducing friction in an internal combustion engine, said complex comprising the reaction product of alkoxylated amine, acid and adenine and having formula (I), wherein Z is derived from either a hydrocarbylsalicylic acid, trithiocyanuric acid, a hydrocarbylsulfonic acid, a dihydrocarbyldithiophosphoric acid or a dihydrocarbyldithiobenzoic acid and wherein R is a hydrocarbyl group of 2 to 22 carbon atoms, R1 is hydrogen or a hydrocarbyl group of 1 to 20 carbon atoms, x and y are each independently integers of from 1 to 15 with the proviso that the sum of x + y is from 2 to 20, and a, b and c are independent numbers from 1.0 to 3.0 wherein the ratios of a:b, a:c and b:c range from 1.0:3.0 to 3.0:1Ø

Description

21~6~6 LUBF~ICANT COMPOSITIONS CONTAINING COMPLEXES OF ALKOXYLATED
AMINE, ACID, AND ADI~NINE

This invention relates to a composition of matter c~l"ai"iny a complex being the reaction product of alko)~ylated amine, acid and adenine and to an improved lubricating oil composition co~ ini"~ the ,~acli~n product and to the use of such complexes to reduce friction and/or improve fuel economy andlor inhibit copper corrosion in an i"ler"al combustion engine.
There are many insl~"ces, as is well known, particularly under "Boundary Lubrication" condiliol Is where two rubbing surfaces must be lubricated, or otherwise prolecled, so as to prevent wear and to insure continued movement Moreover, where, as in most cases, friction between the two surfaces will increase the power required to effect moven~ent and where the movement is an integral part of an energy conversion system, it is most desirable to effect the lubrication in a manner which will minimise this friction. As is also well known, both wear and friction can be reduced, with various degrees of success, through the addition of a suitable additive or combination thereof, to a natural or synthetic lubricant Similarly, continued movement can be insured, again with varying degrees of success, through the addition of one or more a,v,c,rupl iaLe additives.

In order to ~,ruLecl internal combustion engines from wear, engine lubricating oils have been provided with antiwear and antioxidant additives. Theprimary oil additive for the past 40 years for providing antiv~ear and antioxidant properties has been zinc dialkyldithiophosphate (ZDDP). For example, U.S
Patent, 4,575,431 discloses a lubricating oil additive cG,~ osition coi llail-ing dihydrocarbyl hydrogen dithiophosphates and a sulfur-free of hydrocarbyl dihydrogen phosphates and dihydrocarbyl hydrogen phosphates, said composition being at least 50% neutralized by a hydrocarL,yl amine having 10 to 30 carbons in said hydloc~rl~yl group. U.S. Patent 4,089,790 discloses an extreme-pressure lubricating oil containing (1 ) hydrated F)otassium borate, (2) an antiwear agent selected from (a) ZDDP, (b) an ester, an amide or an amine salt of a dihydrocarbyl dithiophos,ut,oric acid or (c) a zinc alkyl aryl sulfonate and (3) an oil-soluble organic sulfur compound. Oil formulations containing ZDDP, hov"ever,require friction modifiers in order to reduce energy losses in overcoming friction Such energy losses results in lower fuel economy. Moreover, oil additive packages contai.,ing ZDDP have enviror""e,1lal drawbacks. ZDDP adds to CONFIRMATION COPY

WO 94/19437 21 S 6 6 ~ 6 2 PCT/EP94/00522 ~

engine deposits which can lead to increased oil consu~,,uLion and emissions.
Moreover, ZDDP is not ash-free. Various ashless oil additive packages have been developed recently due to such environmental concerns. However, many ashiess additive packages tend to be corrosive to copper which leads to 5 additional components in the additive package to protect against COIfOSiOn. Most current commercial engine oils conlain reduced phosphorus due to the poisoning of the catalytic converters by phosphorus.

U.S. Patent No. ~,076,~45 discloses a lubricating oii composition 10 co"laii~ing an amine salt of a dithiobenzoic acid. The amines used to prepare salts are long chain hydrocarbyl amines.

U.S. Patents 3,849,319 and 3,951,973 describe lubricant compositions containing di- and tri(hydrocarbylammonium)trithiocyanurates. The hydrocarbyl 15 radicals include alkyl, aralkyl, aryl, alkaryl and cycloalkyl and the examples are directed to atkylamines. These lubricant compositions were stated to have improved load-carrying properties.

It v\/ould be desirable to have a lubricating oil additive which provides 20 excellent antiwear, antioxidation, friction reducing, fuel economy and environmentally beneficial (less fuel, less phosphorus, i.e., less exhaust emissions) properties while. It is also desirable to find additives which inhibit copper corrosion. It would be a further benefit if these additives do not contribute phosphorous to the lubricating oil composition.
This invention relates to a novel composition of matter containing alkoxylated amine, acid, and adenine. It also relates to an improved lubricating oil composition which reduces friction and/or improves fuei economy in an internal combustion engine and in some cases exhibit improved copper corrosion 30 inhibition and/or antiwear and antioxidant properti~s.

3~

2~5~
wo 94/19437 3 pcTlEp94loos22 The present invention provides a composition of matter v"hich comprises the reaction product of alkoxylated amine, acid and adenine wherein said reaction product is a complex having the following formula ~I) ~R1 ,(CH2CH20) XH ~

( CH2 CH2 0 ) yH ~ 3 wherein Z is derived from either a hydrocarbylsalicylic acid, trithiocyanuric acid, a hy~l oca~ bylsulfonic acid, a dihydrocarbyldithiophosphoric acid or a dih~/dlocalbyldithiobenzoic acid and wherein R is a hyd,-oca,l~yl group of 2 to 22 carbon atoms, R1 is hydrogen or a hydrocarbyl group of 1 to 20 carbon atoms, x 15 and y are each independently integers of from 1 to 15 v"ith the proviso that the sum of x + y is from 2 to 20, and a, b and c are independent numbers from 1.0 to3.0 wherein the ratios of a:b, a:c and b:c range from 1.~:3.0 to 3.0:1Ø

In a further aspect of the present invention there is provided a lubricant 20 composition comprising a major amount of a lubricating oil basestock and a minor amount of a complex having the formula ~I).

In a further aspect the present invention provides for the use of a complex having the formula (I) set forth above for inhibiting copper corrosion associated 25 with the use of lubricating oil compositions in an internal combustion engine.

In a further aspect the present invention provides for the use of a complex having the formula (I) set forth above for reducing friction andlor improving fùel economy in an intemal combustion engine.
The present invention also provides for the use of a complex having the formula (I) set forth above for reducing wear in an internal combustion engine.

in the lubricating oil co,l,,~.osiLion of the present invention, the lubricating oil 35 will contain a major amount of a lubricating oil basestock. The lubricating oil basestocks are well known in the art and can be derived from natural lubricatingoils, synthetic lubricating oils, or mixtures thereof. In general, the lubricating oil wo 94/19437 21~ PCTIEP94/00522 ~

basestock will have a kinematic viscosity ranging from about 5 to about 10,000 cSt at 4ûC.

Natural lubricating oils include animal oils, vegetable oils (e.g., castor oil 5 and lard oil), petroleum oils, mineral oils, and oils derived from coal and shale.

Synthetic oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, as well as their 10 derivatives, analo~s, and homologues thereof, and the like. Synthetic lubricating oils also include alkylene oxide polymers, interpolymers, copolymers and derivatives thereof wherein the terminal hydroxyl groups have been modified by esterification, etherification, etc. Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids with a variety of alcohols. Esters 15 useful as synthetic oils also include those made from C~s to C12 monocarboxylic acids and polyols and polyol ethers.

Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils) comprise another useful class of 20 synthetic lubricating oils. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, polyalphaolefins, and the like.

The lubricating oil may be derived from unrefined, refined, rerefined oils, or 25 mixtures thereof. lJnrefined oils are obtained directly from a natural source or synthetic source (e.g., coal, shale, or tar sands bitumen) Yvithout further purification or treatment. Examples of unrefined oils include a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterification process, each of 30 which is then used without further treatment. Refined oils are similar to theunrefined oils except that refined oils have been treated in one or more purification steps to improve one or more properties. Suitable purification techniques include distillation, hydrotreatin~, dewaxing, solvent extraction, acid or base extraction, filtration, and percolation, all of which are known to those skilled 35 in the art. Rerefined oils are obtained by treating refined oils in processes similar to those used to obtain the refined oils. These rerefined oils are also known asreclaimed or reprocessed oils and often are additionally processed by techniquesfor removal of spent additives and oil breakdown products.

~ WO 94/19437 215 ~ 6 0 ~ 5 PCT/EP94/00522 In the oil soluble complexes of the present invention having the formula (I), R is preferably a hydrocarbyl group of from 2 to 18 carbon atoms, especially 6 to 18 carbon atoms, and R1 is preferably hydrogen or a hydrocarbyl group of from 1 5 to 16 carbon atoms, most preferably hydrogen. Such hydrocarbyl groups includesaliphatic (alkyl or alkenyl~ and alicyclic groups. The aliphatic or alicyclic groups may be substituted with amino, hydroxy, merca~to and the like and may be interrupted by O, S or N. The sum of x~y is preferably 2 to 15.

1û The complexes of the present invention are prepared from the reaction of alkoxylated, prefer~bly a propoxylated or ethoxylated, especially ethoxylated amines with acid and adenine. Adenines are col"~,ercially available or may be prepared by methods known in the art. Adenine may be purchased from Aldrich Chemical Company. Ethoxylated andJor propoxylated amines are commercially 15 available from Sherex Chemicals under the trade name Varonic and from Akzo Corporation under the trade names Ethomeen~), Ethoduomeen/~ and Propomeen~. Examples of preferred amines include ethoxylated (5) cocoalkylamine, ethoxylated (2) tallowalkylamine, ethoxylated (15) cocoalkylamine and ethoxylated ~5) soyaalkylamine and ethoxylated (10) 20 stearylamine. Propoxylated may be substituted for ethoxylated amines.

The complexes of the present invention are the reaction product of:

(a) an alkoxylated, preferably a propoxylated or ethoxylated, especially an 25 ethoxylated amine of the formula:

~ ( CH2C$~20 ) XH
N~
( CH2 CH2 O ) yH
wherein R, x and y are as defined above, (bl an acid being either a hydrocarbylsalicylic acid, trithiocyanuric acid, a 3~ hydrocarbylsulfonic acid, a dihydrocarbyldithiophosphoric acid or a dihydrocarbyldithiobenzoic acid, and WO 94/19437 6 PCT/EP94/00522 ~
21~66~6 (c) an adenine of the formu1a:
~H~

b where R1 is as defined above.

Ple~r,ed hydrocarbylsalicylic acids used to react with alkoxylated amines and adenines to form the complexes of the present invention have the follov~/ingformula:
OH
1 5 ~COOH
Rl wherein R1 is a hydrocarbyl group of from 2 to 30 carbon atoms preferably a hydrocarbyl group of from 2 to 26 carbon atoms. Such hydrocarl~yl groups includealiphatic ~alkyl or alkenyl3 and alicyclic group. The aliphatic and alicyclic groups may be substituted with hydroxy, alkoxy, cyano, nitro, and the like and the alicyclic groups may contain O, S, or N as hetero atoms. These substituted salicylic acids are commercially available or may be prepared by methods knowr in the art, e.g. U.S. Patent 5,023,366.

Trithiocyanuric acid may exist in different tautomeric forms represented by formulas 11, 111 or mixtures thereof:
3û
~H

CyC~

II III

~ WO 94/19437 21~ 6 ~ Q ~ 7 PCT/EP94/00522 Trithiocyanuric acid is prepared by methods well known in the art. These methods involve the treatment of cyanuric chloride with sulfur nucleophiles according to the following reaction scheme:

gl ~H

~/ ~ + 3 NaHS ~ 3 NaCl C~ ~ C1 ~IS ~ SH

Other sulfur nucleophiles which may be employed in the above reaction scheme include sodium sulfide, thiourea and thioacetic acid.

Preferred hydrocarbylsulfonic acids used to react with alkoxylated amines 20 and adenines to form the complexes of the present invention have the following formula:

~SO3H
Rl wherein R1 is a hydrocarbyl group of from 2 to 30 carbon atoms preferably a hydrocarbyl group of from 2 to 26 carbon atoms. Such hydrocarbyl groups include 30 aliphatic (alkyl or alkenyl) and alicyclic group. The aliphatic and alicyclic groups may be substituted with hydroxy, alkoxy, cyano, nitro, and the like and the alicyclic groups may contain O, S, or N as hetero atoms. These sulfonic acids are commercially available or may be prepared by methods well known in the art.

Preferred dihydrocarbyldithiophosphoric acids used to react with alkoxylated amines and adenines to form the complexes of the present invention have the following formula:

wo 94/19437 ~ ~ ~ 6 ~ ~ ~ 8 PcT/EPs4/oos R ~

wherein R2 and R3 are each independentiy hydrocarbyl groups having from 3 to 30 carbon atoms preferably 3 to 20 carbon atoms. Such hydrocarbyl groups include aliphatic (alkyl or alkenyl) and alicyclic group. The aliphatic and alicyclic groups may be substituted with hydroxy, alkoxy, cyano, nitro, and the like and the alicyclic groups may contain 0, S, or N as hetero atoms. Especially preferred dialkyldithiophosphoric acids are made from mixed (85%) 2-butyl alcohol and ( 15%) isooctyl alcohol (mixed primary and secondary alcohols).
Dihydrocarbyldithiophosphoric acids may be purchased from Exxon Chemical Company Preferred dihydrocarbyldithiobenzoic acids used to react with alkoxylated amines and adenines to form the complexes of the present invention have the following formula:
R3 ,R2 R4 ~ C~
R5>~ S~

wherein R2 to R6 are each preferably hydrogen; a hydrocarbyl group containing from 1 to 18 carbon atoms; or a hydroxy group with the proviso that at least one of R2 to R6 is a hydrocarbyl, preferably an alkyl group containing 1 to 18 carbon atoms, more preferably 1 to 6 carbon atoms. R3 and R5 are most preferably t-butyl groups and R4 is preferably hydroxy. The sum of x + y is preferably 2 to15. The hydrocarbyl groups include aliphatic (alkyl or alkenyl) and alicyclic groups which may be substituted by hydroxy, amino, cyano and the like and may be interrupted by 0, S or N.

~ wo 94/19437 9 215 6 ~ ~ ~ pcTlEps4loo~722 Dithiobenzoic acids may be prepared from a phenol according to the following method. A Phenol of the formula:

R3~R2 >-OH
R5>~CR6 is dissolved in a solvent such as dimethylsulfoxide and treated under nitrogen with potassium hydroxide dissolved in a minimum amount of v~/ater. Carbon disulfide is then added under nitrogen to this mixture which is maintained at about room temperature. The resulting reaction mixture is heated at between 25 to 100C for15 1-3 hours and then added to an acidified water solution. The resulting dithiobenzoic acid can be isolated by solvent extraction using, e.g. ether and the solvent evaporated.

When the complexes of the present invention are derived from a 20 hydrocarbylsalicylic acid they are prepared by adding the salicylic acid to amixture of adenine and alkoxylated amine. Because of the exothermic nature of the reaction, the reaction mixture should be stirred during addition of salicylic acid.

When the complexes of the present invention are derived from trithiocyanuric acid they are prepared by adding trithiocyanuric acid to a mixture of adenine and alkoxylated amine. Because of the exothermic nature of the reaction, the reaction mixture should be stirred during addition of trithiocyanuric acid. The amounts of reactants are approximately stoichiometic, although a slight excess of trithiocyanuric acid, which has three reactive hydrogens7 may be employed.

When the complexes of the present invention are derived from a dihydrocarbyldithiobenzoic acid they are prepared as described below. This preparation is based on an approximate 1:1:1 mole ratio although this ratio may vary. About 10 to 20% of the required amount of alkoxylated amine (based on the thiobenzoic acid) is added to the dithiobenzoic acid with heating and stirring.
Temperatures may range from about 25 to about 180C. About 10 to 20% of the WO 94/19437 2 1 5 6 ~ O S 10 PCT/EP94/00522 ~

required amount of adenine is then added. This sequential addition process is repeated until the required amount (based on the above approximate 1:1:1 of amine:acid:adenine) is reached. A precipitate (polymeric and ~nidentified material) forms if this alternative additional procedure is not employed.

When the complexes of the present invention are derived from a hy~roc~,~ylsulfonic acid they are prepared by adding the sulfonic acid to a mixture of adenine and al~oxylated amine. Because of the exothermic nature of the reaction, the reaction mixture should be stirred during addition of sulfonic acid.
When the complexes of the present invention are derived from a dihyd~oca~byldithiophosphoric acid they are prepared as described below. This ,~reparalion is based on an approximate 1:1:1 mole ratio although this ratio mayvary. About 10 to 20% of the required amount of alkoxylated amine (based on the 15 phosphoric acid) is added to the dihydrocarbyldithiophosphoric acid with heating and stirring. Temperatures may ran~e from about 25 to about 1 80C. About 10 to 20% of the required amount of adenine is then added. This sequential addition process is repeated until the required stoichiomel:ic amounts (1:1:1 of amine :acid:adenine) is reached. A precipitate (polymeric and unidentified material) 20 forms if this sequential addition procedure is not employ~d.

The precise stoichiometry of the bonding in the complexes of the formula (I) is not known since each molecule in the complex may have several sites which can take part in the hydrogen bonding process either as an acceptor or donor.
25 Because of the multiplicity of bonding possibilities, the molar ratios a:b:c can be varied over a wide range based on the donor/acceptor sites on each of the three molecules and therefore a, b and c in formula (I) are numbers which are not necessarily integral. When the acid is trithiocyanuric acid there exist a total of forty-five combinations of interaction sites between the three molecules 30 comprising the complex of the formula (I). When the acid is hydrocarbylsulfonic or hy~lroca-bylsalioylic acid there exist a total of thirty combinations of interaction sites between the three molecules comprising the complex of the formula (I).
When the acid is dihydrocarbyldithiobenzoic or dihydrocarbyldithiophosphoric ~cid there exist a total of fifteen combinations of interaction sites between the 35 three molecules comprising the complex of the formula (I). For example a:b:c may be 1:2:1 or 1:1:3.

21 56~ G
~ WO 94/19437 11 PCT/EP94/00522 ., ;, ~ j ~ I ,..

The lubricant oil composition according to the invention comprises a major amount of lubricating oil basestock and a minor amount. of the alkoxylated amine:acid:adenine complex. When the acid is either trithiocyanuric acid, hydrocarbylsulfonic acid or hydrocarbylsalicylic acid typically, the amount of 5 complex will be from about 0.001 wt% to about 5 wt%, based on oil basss~ock.
er~bly, the amount of amine salt is from about 0.05 wt% to about 1.0 wt%.
When the acid is either dihydrocarbyldithiobenzoic acid or dihydrocarbyldithiopl~os~Jl,oric acid the conc~"l,alion of the complex of general formula (I) mat typically range from 0.1 to 5 wt% based an oil and ,c rererably from 10 0.5 to 1.5 w~%. The amount of complex is such that there is an e~ective amount to achieve one or more of improved fuel economy, reduced friction, inhibition of copper corrosion, antiwear properties and antioxidant properties when the lubricant oil composition is used in an intemal combustion engine.

If desired, other additives known in the art may be added to the lubricating oil basestock. Such additives inclu~e dispersants, antiwear agents, antioxidants, rust inhibitors, other corrosion inhibitors, detergents, pour point depressants,extreme pressure additives, ViSCDSity index improvers, other friction modifiers,hydrolytic stabilizers and the like. These additives are typically disclosed, for 20 example, in "Lubricant Additives" by C. V. Smalhear and R. Kennedy Smith, 1967, pp. 1-11 and in U.S. Patent4,105,571.

The lubricating oil composition of this invention can be used in the lubrication system of essentially any internal combustion engine, including 25 automobile and truck engines, two-cycle engines, aviation piston engines, marine and railroad engines, and the like. Also contemplated are lubricating oils for gas-fired engines, alcohol (e.g., methanol) powered engines, stationary powered engines, turbines, and the like.

This invention may be further understood by reference to the following example, which includes a prererled embodiment of the invention.

ExamPle 1 3~ This Example ill~sLra~es the preparation of a complex containing ethoxylated amine, trithiocyanuric acid and adenine according to the invention.
68 g of ethoxylated~5)cocoalkylamine and 13 9 of adenine was heated to 70C
with stirring in a 3-neck round bottom flask fitted with a thermometer and a water WO 94119437 2 1 5 6 6 ~ ~ 12 PCTIEP94/00522 ~

cooled condenser. 14 9 of trithiocyanuric acid was added gradually to the stirred amine solution. Durin~ addition, the temperature rose to 1 05C due to an exothermic reaction between acid and amine adenine components. The reaction mixture was used without further purification.

ExamPle 2 The complex containing ethoxylated amine, trithiocyanuric acid and adenine is an effective friction modifier as shown in this example. The Ball on 10 Cylinder ~BOC) friction tests were performed using the experimental proceduredescribed by S. Jahanmir and M. ~eltzer in ASLE Transaction, Vol. 29, No. 3, p.
425 (1985) using a force of 0.8 Newtons (1 Kg) applied to a 12.5 mm steel ball in contact with a rotating steel cylinder that has a 43.9 mm diameter. The cylinderrotates inside a cup containing a sufficient quantity of lubricating oil to cover 2 mm 15 of the bottom of the cylinder. The cytinder was rotated at 0.25 RPM. The friction force was continuously monitored by means of a load transducer. In the tests conducted, friction coerliciel,ls attained steady state values after 7 to 10 turns of the cylinder. Friction experiments were conducted with an oil temperature of 100~C. Various amounts of the complex prepared in Example 1 were added to 20 solvent 150 N. The results of BOC friction tests are shown in Table 1.

Wt% of Ethoxylated(5)Cocoalkylamine, Coefficient Adenine, Trithiocyanuric Acid of Friction Complex in Solvent 1 50N~

0 OO 0.29 0 05 0.06 0.1 005 0.2 005 0.3 0.05 0.5 0.025 0.8 0.025 1.0 0.01 0 2I5~
WO 94tl9437 '13 PCT/EP94/00522 * S150N is a soivent extracted, ciewax~ hyd~o~i-ned neutral lube base stock obtained from approved par~inic crudes ~vls~sjty, 32 cSt at 4~C, 150 Saybolt seconds~

As can be seen ~rom the results in Table 1, as ~ittle as 0.05 wt% of complex shows 79% decrease in the coefficient of friction. These results demonstrate that p~esent complexes are capable of significant reductions in the coefficient of fric~n of a lubricant ~asestock which results in Jess friction and hence greaterfuel economy when the I~J~ricated oil is used in an i"Lerl ,al combustion engine.
Example 3 This Example illustrates the preparation of a complex containing an ethoxylated amine, alkylsalicylic acid and adenine according to the invention.
1019 of ethoxylated(5)cocoalkylamine and 4 9 of adenine were heated to 80~C
with stirring in a 3-neck round bottom flask fitted with a thermometer and a water ccoled condenser. 100 g of salicylic acid having the formula OH
~
~COOH
C15~ 1 was added gradually to the stirred amineladenine solution. During addition, the temperature rose to 104C due to the exothermic reaction between acid and amine. The reaction mixture was maintained at 104C for 1.5 hours and then cooled to room temperature. The reaction mixture was a complex according to the invention and was used without further purification.
Example 4 The complex containing ethoxylated amine, alkylsalicy~ic acid, adenine is an effective friction modifier as shown in this example. The Ball on Cylinder (BOC) friction tests were performed using the experimental procedure described in Exampie 2. Various amounts of complex prepared in Example 3 were added to solvent 150 N. The results of BOC friction tests are shown in Table 2.

WO 94/19437 14 PCTIEP94/00522 ~
2l~6a~
TABLE 2 ~

Wt% of Ethoxylated(5)Cocoalkylamine,Coe~ficient Alkyl Salicylic Acid and Adenine of Friction Complex in Solvent 150N

0.32 0.1 0.07 0.2 005 0.3 ~.035 0.5 0.03 0.8 0.03 1.0 0.02 As can be seen from the results in Table 2, as little as 0.1 wt% of complex 5 shows a 78% decrease in the coefficient of ~iction. These results demonstrate that the present complexes are capable of significant reductions in the coefficient of friction of a lubricant basestock which results in less friction and hence greater fuel economy when the lubricated oil is used in an internal combustion engine.

10 Example 5 A solution of 3 g ethoxylated (5) cocoalkylamine was heated to 50-110C
with stirring. 0.5 g of 4-hydroxy-3,5-ditertiarybutyldithiobenzoic acid v"as then added to the heated and stirred solution following by 125 mg of adenine. This 15 procedure of sequentially adding the dithiobenzoic and adenine v~as repeated until 2 9 of the acid and 50 mg of adenine have been added to the solution. The sequential procedure was employed to prevent precipitation of by-product polymeric materials.

20 Example 6 Ball on Cylinder ~BOC) friction tests were performed on the ethoxylated(5)cocoalkylamine:dithiobenzoate:adenine complex from Example 5 in solvent 150N base oil using several concentrations of the additive. The BOC
25 tests v~ere performed using the experimental procedure described in Example 2.
The data is shown in Table 3.

5 ~ ~
~ WO 94/19437 15 PCT/EP94/00522 ,, ;

Coefficient of Friction Pt Concentration (wt.%)Ethoxylated (5) Ethoxylated (5) Primene~
in solvent 150Ncoco~,l,i,le:DTB:cocoamine:DTB JMT:DTB
Adenine 0 0.37 0.37 0.37 2 0.05 0.22 0.121 --3 0.1 0.17 0.107 0.3 4 0.2 0.13 -- --0 4 _ 0.107 - -6 ~ 007 -- 0.21 7 0.6 -- 0.107 --8 0.8 0.06 0.107 0.177 ** Primene JMT is predominantly a C18 t-alkyl primary amine manufactured 5 by Rohm & Haas.

As can be seen from the data in Table 3, the adenine-containing complex achieves lower coefficient of friction than can l~e obtained from the comparablecomplex without adenine or a Primene JMT:DTB complex.
Example 7 This Example illustrates the preparation of a complex containing ethoxylated amine, alkylsulfonic aGid and adenine according to the invention. 4115 g of ethoxylated(2)tallowamine and 1 g of adenine were heated to 60C with stirring in a 3-neck round bottom flask fitted with a thermometer and a water cooled condenser. 58 g of alkylsulfonic acid having the formula ~3So3H
C2~H~9 WO 94/19437 2 1 ~ 6 6 ~ ~ 16 PCT/EP94/00522 ~

was added gradually to the stirred amineladenine solution. During addition, the te",peral~lre rose to 105C due to the exothermic reaction between acid and amine. The reaction mixture was maintained at 105C for 1.5 hours and then cooled to room temperature. The reaction mixture was a complex according to t~e 5 invention and was used without further purification.

Example 8 The complex conla~"in~ ethoxylated amine, alkylsulfonic acid and adenine 10 is an effective friction modifier as shown in this example. The Ball on Cylinder (BOC) friction tests were performed using the experimental procedure described in Example 2. Various amounts of complex prepared in Example 7 were added to solvent 150 N. The results of ~OC friction tests are shown in Table 4.

Wt% of Ethoxylated(2)Tallowamine, Coefficient Alkylsulfonic Acid and Adenine Complex of Friction in Solvent 1 5QN

o oo 0.32 0.1 0.20 0.2 0.18 0.3 ~.13 0.5 0 1 0 0.8 0.07 1 0 0.06 As can be seen from the results in Table 4, as little as 1.0 wt% of comp~ex 2û shows an 81% decrease in the coefficient of friction These results demonstrate that the present complexes are capable of si~nificant reductions in the coefficient of friction of a lubricant basestock which results in less friction and hence greater fuel economy when the lubricated oil is used in an internal combustion en~ine.

215B6~ 6 WOg4/19437 17 PCT/EP94/00522 Example 9 This Example iiiustrates the preparation of the novel complex of the invention. A solution of 80 g of diisooctyldithiophosphoric acid was heated to 50-100C with stirring. 10 9 of ethoxylated(5)cocoalkylamine v~as then added to theheated and stirred solution followed by 1 g of adenine. This procedure of sequentially adding ethoxylated amine and adenine was repeated until 75 9 of ethoxylated (5~ cocoalkylamine and 7 9 of adenine have been added to the solution. The seguential addition ,~roced.~re was employed to prevent precipitation of byproduct. The complex was then collected on cooling and used without further purification.

Example 10 1~ This Example illustrates the superior copper corrosion provided by the complex of the inYention as prepared in Example 9. The test for copper corrosionwere run as follows. Copper corrosion tests were based on ASTM D-2440. 25 9 of oil sample is placed in a 0.5" test tube with 30 cm of copper wire coiled to 0.5"
~nd stretched to a finished length of 2". The test tube is then heated at 110C for 120 hours. Nitrogen is bubbled through the oil at 17 cc~min during the test period.
A 5 9 sample of oil is removed at the end of the test and analyzed for copper content. Results of the copper corrosion are shown in Table ~.

WO 94/19437 2 1 ~i 6 ~ 18PCT/EP94/00522 Copper Corrosion (ppm~

Base case - Lubricating oil 21 Base case +1% Ethoxylated(5)cocoamine:DDP(diisooctyl) 37 Base case +1% Ethoxylated~5)cocoamine:DDP(diisooctyl): 17 Adenine Base case +1.5% Ethoxylated(5)cocoamine:DDP(diisooctyl) ~7 ~ase case +1.5% Ethoxylated(5)cocoamine:DDP(diisooctyl): 23 Adenine Base case ~1% Ethoxylated(2)tallowamine:DDP5secondary 74 ~*
Base case +1% Ethoxylated(2~tallowamine:DDP(secondary 18 ):Adenine Base case +1.5% Ethoxylated~2)tallowamine:DDP(seco~,dar~f 107 Base case ~1.5% Ethoxylated(2)tallowamine:DDP~secondary 23 ):Adenine DDP ~secondary) contains a mixture of isobutyl (85%) and isooctyl (15%) as the alkyl component Example 1 1 This Example illustrates the superior antiwear properties of the complex of 10 the invention. Antiwear properties are measured by the four-ball wear test asfollows. The Four Ball test used in described in detail in ASTM method D-2266.
In this test, three balls are fixed in a lubricating cup and an upper rotating ball is pressed against the low~r three balls. The test balls utilized were made of AISI52100 steel with a hardness of 65 Rockwell C (84û Vickers) and a centerline 15 roughness of 25 mm. Prior to the tests, the test cup, steel balls, and all holders were washed with 1,1,1 trichloroethane. The steel balls subsequently v.~ere 21~6~
WO 94/19437 19 . PCT/EP94/00522 washed with a laboratory detergent to remove any solvent residue, rinsed with water, and dried under nitrogen.

The Four Ball wear tests vrere performed at 100C, 60 kg load, and 1200 5 rpm for 45 minutes duration. After each test, the balls were washed and the Wear Scar Diameter (WSD) on the lower balls measured using an optical microscope.
Using the WSD's, the wear volume (WV) was calculated from standard equations (see Wear Control Handbook, edited by M. B. Peterson and W. 0. Winer, p. 451, American Society of Mechanical En~ineers ~1980]~. The percent v~/ear reduction 10 (% WR) for each oii tested was then calculated using the followin~ formula.

%WR = ( 1--WV with additiveM~ without additive) x 100 The result of the four-ball are set forth in Table 6.

Wear Scar Diameter (mrn) %Additive Ethoxylated(5)cocoamine: Ethoxylatedt5)cocoamine:
in Solvent 150N* DDP(isooctyl) DDP(isooctyl):Adenine % wear volume reduction % wear volume reduction 0 0.0 0.0 0.1 -7.3 15.5 û.2 45.5 88.1 0.4 41.1 --0.5 -- 96.4 0.6 -- 97.8 0.8 15.1 99.2 1.0 -7.3 99.5 1.5 96.1 99.5 * S150 is a solvent extracted, dewaxed, hydrofined neutral lube base stock obtained from approved paraffinic crudes (viscosity, 32 cSt at 40C, 150 Sayboit seconds~

WO 94/19437 2 1 5 6 6 3 ~ 20 PCT/EP94/00522 ~

The data in Table 6 demonstrate that even at low concentration (C0.2%), the present adenine complex has superior antiwear properties over the correspondjng amine salt without adenine.

Claims

CLAIMS:

1. A composition of matter comprising a complex which is the reaction product of alkoxylated amine, acid and adenine, said complex having the formula (I):

(I) wherein Z is derived from either a hydrocarbylsalicylic acid, trithiocyanuric acid, a hydrocarbylsulfonic acid, a dihydrocarbyldithiophosphoric acid or a dihydrocarbyldithiobenzoic acid and wherein R is a hydrocarbyl group of 2 to 22 carbon atoms, R1 is hydrogen or a hydrocarbyl group of 1 to 20 carbon atoms, x and y are each independently integers of from 1 to 15 with the proviso that the sum of x + y is from 2 to 20, and a, b and c are independent numbers from 1.0 to3.0 wherein the ratios of a:b, a:c and b:c range from 1.0:3.0 to 3.0:1Ø

2. A composition as claimed in claim 1 wherein Z is derived from a hydrocarbylsulfonic acid of the following formula:

wherein R1 is a hydrocarbyl group having from 2 to 30 carbon atoms.

3. A composition as claimed in claim 1 wherein Z is derived from a hydrocarbylsalicylic acid of the following formula:

wherein R1 is a hydrocarbyl group having from 2 to 30 carbon atoms.

4. A composition as claimed in claim 2 or claim 3 wherein R1 is a hydrocarbyl group having from 2 to 26 carbon atoms.

5. A composition as claimed in claim 1 wherein Z is derived from a dihydrocarbyldithiobenzoic acid of the following formula:

wherein R2 R3 R4 R5 and R6 are independently hydrogen or a hydrocarbyl group containing from 1 to 24 carbon atoms or a hydroxy group with the proviso that atleast one of R2 to R5 is a hydrocarbyl group.

6. A composition as claimed in claim 5 wherein R4 is hydroxy.

7. A composition as claimed in either claim 5 or claim 6 wherein at least one of R2 to R6 is alkyl containing from 1 to 18 carbon atoms.

8. A composition as claimed in any of claims 5 to 7 wherein R3 and R5 are t-butyl.

9. A composition as claimed in claim 1 wherein Z is derived from a dihydrocarbyldithiophosphoric acid which has the following general structure;

wherein R2 and R3 are each independently hydrocarbyl groups having from 3 to 30 carbon atoms.

10. A composition as claimed in claim 9 wherein R2 and R3 are alkyl or alkenyl groups of from 3 to 20 carbon atoms.

11. A composition as claimed in any of claims 1 to 10 wherein R is alkyl or alkenyl of from 6 to 18 carbon atoms.

12. A composition as claimed in any of claims 1 to 11 wherein the sum of x+y is 2 to 15.

13. A composition as claimed in any of claims 1 to 12 wherein in the adenine R1 is hydrogen.

14. A lubricating oil composition for internal combustion engines which comprises (a) a major amount of a lubricating oil basestock and (b) a minor amount of a complex as claimed in any of claims 1 to 13.

15. A composition as claimed in claim 14 wherein the complex is as claimed in any of claims 5 to 11 and wherein the amount of complex is from about0.1 to about 5.0 wt.%, based on oil basestock.

16. A composition as claimed in claim 14 wherein the complex is as claimed in any of claims 1 to 4 and wherein the amount of complex is from about 0.001 to about 5.0 wt.%, based on oil basestock.

17. The use in a lubricating oil composition of a complex as claimed in any of claims 1 to 13 for improving fuel economy in an internal combustion engine.

18. The use in a lubricating oil composition for reducing wear and/or inhibiting copper corrosion in an internal combustion engines of a composition as claimed in any of claims 1 to 13.

19. The use of a composition as claimed in any of claims 1 to 13 as a friction modifier in a lubricating oil composition for an internal combustion engine.